// Formula for expanding a large random access file when it runs out of space.// presume DaysBetweenDefrags = 7 if you have no better information.long newSize = currentSize + expectedGrowthPerDay * DaysBetweenDefrags;// If you have no estimate for expected growth, use this formula// to grow it by 10%, rounded up, whenever it runs out of space.// The file may be initially become very fragmented but should// settle down after the first defrag.long newSize = (currentSize * 110 + 99)/ 100;